Liquid dispensing apparatus



Oct. 9, 1962 A. L. JAPP LIQUID DIsPENsING APPARATUS Filed Nov. 25, 1959IN V EN TOR. ,IMBERT L JPP Y ATTORNEY GOG@ United States atent 3,057,518LHQUID DHSPENSIN G APPARATUS Albert L. Kapp, Amityville, N.Y., assignorto Gulf Oil Corporation, Pittsburgh, Pa., a corporation of Penn-Sylvania Filed Nov. 25, 1959, Ser. No. 355,318 4 Claims. (Cl. 222-459)This invention relates to a liquid dispensing apparatus and moreparticularly to a liquid dispensing apparatus that is adapted to deliveran accurately metered liquid at a relatively high velocity and volumeper unit of time.

Liquid dispensing systems of the type designed to deliver liquids suchas distillate fuel oils, that is, domestic furnace heating oils or thelike, have heretofore involved withdrawing liquid from a storage tank bymeans of a pump, subsequent passage through an air eliminator, meter,and then through a delivery hose of relatively large cross-sectionalarea, at a relatively low velocity and volume ow per unit of time. Suchsystems have not proved entirely satisfactory because of the relativelylarge lamount of time consumed in effecting delivery of a given quantityof liquid, and because of the difficulty of handling the delivery hoseand the liquid contained therein.

The use of lightweight, small-diameter delivery hose has been proposedbut rejected for the reason that such use, under the same conditions,would increase the amount of time consumed in effecting a liquiddelivery. It also has been proposed to reduce liquid delivery time byuse of either the small or large-diameter delivery hose by passage ofthe liquid through the delivery hose at a relatively higher velocity andvolume per unit of time. This has been found impractical, among otherreasons, because of the high surge pressures-sucient to damage themeter-that develop when liquid ow is started or stopped. Increasing theliquid velocities and volumes in conventional delivery systems is alsoobjectionable for the reason that relatively greater negative pressuresare developed on the suction side of the pump during such operation. Itis necessary to hold the negative pressure in the system to a minimum onthe suction side of the pump as compared With the outside atmosphericpressure, to prevent more air being induced into the suction side of thepump and system than can be expelled by conventional air eliminators ina given interval of time when liquid is pumped through it at arelatively high velocity. This limitation on the negative pressure inthe suction side of the pump and system also is necessary to prevent thepossibility of metering entrained air as liquid.

It has now been found that deliveries of a liquid can be .effected atrelatively high velocity and volume per unit of time with accuratemetering of the liquid, even when them delivery hose is substantiallysmaller than the smallest cross-sectional area of any of the precedingportions of the path of liquid flow, by means of a dispensing systeminvolving a liquid source, an air eliminator, a meter, a receiver tank,and a pump having an inlet and an outlet Iand adapted to `discharge saidliquid from said outlet at a relatively high volume and at a relativelyhigh discharge pressure, all of said elements being connected in seriesin the order mentioned, where the cross-sectional area of the receivertank is substantially greater than that of the pump inlet and the uidcapacity of said receiver tank is substantially greater than that of thepump, and where the meter and receiver tank are positioned at anelevation lower than the liquid source, the dimensions of the path offlow between said liquid source and said receiver tank being such thatthe total friction pressure loss at said relatively high volume is lessthan the pressure resulting from the difference in elevation betweensaid liquid source and said receiver tank, so as to provide low velocityflow 3,057,518 Patented Oct. 9, 1962 ICC by gravity from the liquidsource to the meter and receiver tank.

The receiver tank preferably is also equipped with an air venting deviceand is of suicient cubic capacity effectively to act as a uid baie inpreventing pump cavitation with its attendant noise and vibration. Also,the meter is preferably isolated from the relatively high surge or shockpressures that develop when the liquid delivery flow is shut off bymeans of a reverse flow check valve positioned at the outlet side of thereceiver tank.

In an especially advantageous embodiment, the pump, as well as the meterand receiver tank, is positioned at a lower elevation than the liquidsource, and at the same or lower elevation than the level of the liquidin the receiver tank.

The relative capacities of all components of the dispensing system aresuch that the gravity ilow of accurately metered liquid to the receivertank will be at a lower velocity and substantially higher volume perunit of time than that withdrawn by the pump from the receiver tank inan equal unit of time. When the components and system are so designed,this relationship or potential difference in volume iiowing into and outof the receiver tank will be of a magnitude that will substantiallyoffset the effect of pump suction turbulance, thereby maintaining thereceiver tank full of liquid. Hence, the meter will only measure thevolume of liquid withdrawn and delivered by the pump. n

By arranging all the components having the design characteristicsindicated in the sequence and at the elevations indicated, the highpressures that develop in pumping the liquid at a relatively high volumerate per unit of time through a small-diameter delivery hose will beconfined to the downstream side of the receiver tank and pump, thuspermitting a relatively low-velocity, high-volume flow per unit of timethrough the system upstream of the meter, whereby sufficient time isprovided for the separation of any entrained air from the liquid priorto metering of the latter.

Referring now briefly to the drawing, the FIGURE is a schematicrepresentation of a complete liquid dispensing system involving theprinciples of the present invention.

Taking up the drawing in greater detail, numerals Z, 4, 6, and 8designate Iseparate compartments of tank 10 that is adapted to bemounted on a bed of a truck, trailer or the like, not shown. Tank 10,together with manifold chamber 20, and connecting conduits 12, 14, 16,and 18, comprise the liquid source referred to herein.

To minimize the possibility of a relatively high volume of air becomingentrained in the liquid as -the source tanks or compartments thereofbecome empty, or approach empty, an air eliminator and liquid 'levelcontroller y85 is provided inthe upper portion of manifold 20. When theliquid reaches a predetermined limit or level in the manifold, floatcontroller automatically shuts down the pump, as hereinafter described,until the ow of liquid into the manifold 20 from the source is againre-established, and the manifold 20 is lled with liquid. Any air thatmay have entered the manifold during this transition is evacuated by theair eliminator 85, through vent 25, thereby minimizing any excess ofentrained air which would be measured as liquid as it passed through themeter because of the limitation of available devices for expelling airentrained in the liquid.

Numeral 24 designates an air eliminator or battle chamber, provided witha float controlled vent line 2'5 and connected to the outlet of manifold20. Air eliminator 24 is adapted to facilitate removal of air or vaporfrom the liquid passed therethrough through float-controlled vent line25so that the liquid may be more accurately measured by meter 26,positioned immediately downstream of air eliminator 24 and connectedthereto. Numeral 30 refers to a receiver tank which is connected at itsinlet to the meter 26 and its outlet to pump 36. As indicated, the cubicliquid capacity or content of receiver tank 30 is suiciently great tosubstantially eliminate turbulence with attendant possible cavitation atthe inlet of pump 36. The receiver tank 30 also is equipped with aoatcontrolled vent line 31 to expel the air initially therein -and toprevent the accumulation of air and vapor iu the receiver tank, wherebythe receiver tank will be kept full of liquid. By such means, pumpcavitation, with its attendant noise and hydraulic hammer, is prevented.

In order to avoid development of relatively high Huid velocities throughthe air eliminator 24 and meter 26, with attendant loss of meteraccuracy, the potential difference in flow of liquid by gravity throughthe air eliminator 24 and meter 26 should be substantially lower invelocity and greater in volume per unit of time than that beingwithdrawn from the receiver tank 30 in an equal interval of time anddelivered by pump 36 to etlect satisfactory metering accuracy.

As illustrated by the drawing, all portions of metering and pumpingsections of the system, including the air eliminator 24, meter 26,receiver tank 30, and pump 36 are positioned at an elevation lower thanthe lowest permissible level of the liquid supply source.

Numeral 42 refers to a conduit connecting the outlet side of pump 36with hose reel 78 and with a suitable, small-diameter delivery hose 44.For greatest convenience, the delivery hose 44 should be substantiallysmaller in cross-sectional area than the smallest portion of the path ofliquid flow upstream thereof. Numeral 46 indicates a delivery nozzlehaving7 associated therewith a manually controlled valve. Numerals 22,28, 32, and 42 refer to conduits connecting respectively, the manifold20 and air eliminator 24, meter 26, and receiver vessel 30 and pump 36,and hose reel 78. Numeral 34 denotes a checkvalve to prevent high shockpressures that develop when flow of liquid is shut off by nozzle 46being transmitted to meter 26 and also prevents back flow of liquid whenpump 36 is not in operation.

In operating the system, power take-off handle 50 is moved to the onposition, engaging the power take-off 52 that drives the hydraulic pump54 from the transmission of a vehicle such as a truck, not shown, onwhich tank may be mounted. Power take-off handle 50 also closes anelectrical switch 58 for circuits 60, 62, and 64, and opens acam-operated valve 66 which applies the brakes to the wheels oftheaforesaid vehicle, thereby preventing any movement of the vehicle untilthe power takeott' is disengaged.

The hydraulic pump 54 supplies hydraulic fluid under pressure from avented reservoir 56 through control valve 68 to hydraulic motor 70,which, in turn, drives the pump 36 by means of a direct coupling, beltor chain drive 40. Hydraulic pump 54 also supplies hydraulic powerthrough needle valve 72 and control valve 74 to hose reel motor 76,which drives the hose reel 78.

Circuit 62, which is interlocked through relay 8G, energizes anelectropneumatic cylinder 82 when switch 84 is closed, thereby movingthe vehicle engine throttle, and increasing the engine speed to thatrequired to deliver the liquid at the desired rate.

Circuit 60 is interlocked through a float-controlled switch 86 thatenergizes electropneumatic cylinder 38. Should a compartment of tank 10run dry, float-controlled switch 86 will close, energizingelectropneumatic cylinder 88, admitting air to the cylinder, movingcontrol valve 68 to the ott position, and shutting down the system. Nofurther liquid delivery can be made until another tank compartment valveis opened and the ow of liquid `from the source expels the air inmanifold through vent 2S and the liquid level in the system and manifoldreturns to normal.

Circuit 64 is interlocked through a pressure safety control switch vthat closes when pressure in the system reaches a predetermined maximum,as, for example, when the valve in nozzle 46 is closed. Closure ofswitch 90 energizes relay 80, causing switch 81 to close, wherebyelectropneumatic cylinder 88 is energized, closing valve 68 and shuttingdown hydraulic motor 70, and de-energizing speed controller 82, therebyreducing the engine speed to idle. When the delivery nozzle 46 is nextopened, the pressure in line 42 will drop, permitting pressure controlswitch 90 to open, de-energizing relay 80 and energizing throttlecontroller 82, moving it to a high speed position for again deliveringlthe liquid at the desired rate of flow.

In a specic embodiment, delivery hose 44 has an inner diameter of oneinch, as opposed to conventional fuel oil delivery hose, which has aninner diameter of one and one-fourth to one and one-half inches. Theweight of the smaller hose, including the liquid therein, issubstantially less than that of the conventional hose. Hence the effortexpended in hauling the hose out to make a delivery is, in comparisonwith a conventional, one and one-quarter inch I.D. hose reduced by morethan 50 percent. In this embodiment, liquid is delivered through hose 44at a rate of 75 gallons-per-minute and at a pressure of pounds persquare inch, the rate of delivery of the pump in this instance, asopposed to 45 gallonsper-minute, the conventional rate through a one andonequarter inch diameter hose. ln this embodiment, a meter having anaccurate flow capacity of 125 gallons-per-minute is employed. Sinceliquid is displaced from the system through hose 44 only at `the rate of75 gallons-perminute, and since the potential flow rate of deliverythrough the meter is well above this limit, the velocity of the liquidflowing through the air eliminator is low enough to permit it to expelany entrained air in the liquid and thereby effect a high degree ofmetering accuracy.

It will be understood that the invention is not limited to the specificdetails of the pressure release system, hydraulic control system, orelectrical system of the embodiment shown in the drawing. For example,instead of the pressure release valve 90, there can be employed arecirculating by-pass around pump 36, said by-pass being controlled by aspring-controlled pressure release valve.

Also, a pneumatic or electrical control system can be substituted forthe hydraulic control system shown in the drawing.

Many additional variations and modifications of the invention asdescribed and illustrated herein will occur to those skilled in the `artand such variations and modifications can be resorted to withoutdeparting from the spirit or scope of the invention. Accordingly, theinvention is not to be limited by the embodiments described herein butonly by the scope of the claims appended hereto.

Iclaim:

l. A liquid dispensing system comprising a liquid source, a meter, areceiver vessel, and a pump provided with an inlet and an outlet andadapted to discharge said liquid from said outlet at a relatively highvolume and at a relatively high discharge pressure, said elements beingconnected in the order named and adapted to permit liquid flowtherethrough, air eliminating means positoned upstream of said meter toremove gaseous material from the liquid prior to passage thereof intosaid meter, said meter and said receiver vessel being positioned at alower elevation than said liquid source, the dimensions of the path offlow between said liquid source and said receiver vessel being such thatthe total friction pressure loss at said relatively high volume is lessthan the pressure resulting from the difference in elevation betweensaid liquid source and said receiver vessel, so as to permit lowvelocity, gravity ow through said meter, said receiver vessel beingprovided with controlled, venting means adapted to vent the receivervessel to the atmosphere when the liquid level in said vessel fallsbelow a predetermined level, said receiver vessel also having across-sectional area and liquid capacity substantially greater than thatof the pump inlet and the pump, respectively.

2. The apparatus of claim 1, wherein the pump also is at a lowerelevation than the liquid source.

3. The apparatus of claim 1, where a check-Valve adapted to preventreverse flow of liquid is positioned intermediately of the pump and themeter.

4. The apparatus of claim 1, where the liquid source is provided with amanifold chamber, and where said manifold chamber is provided with aliquid level control means adapted to stop `and starrt said pump when aminimum and maximum liquid level is established in said manifold chamberso as to prevent gaseous materials 6 entering said meter when liquidsource Vessel approaches exhaustion, and where said liquid source isprovided with a vent means adapted to permit escape of gaseous materialswhen the maximum liquid level is being reestablished and before saidpump again withdraws liquid from said receiver vessel.

References Cited in the file of this patent UNITED STATES PATENTS2,075,126 Marden Mar. 30, 1937 2,090,734 Piqurez Aug 24, 1937 2,292,007Morgan Aug. 4, 1942 2,506,911 Teigler May 9, 1950 2,690,712 Foote Oct.5, 1954 2,884,964 Tye May 5, 1959 2,916,880 Hahn Dec. 15, 1959

